Audio user interface apparatus and method

ABSTRACT

A method comprises converting an audio frequency domain signal into one or more voltage signals. Then the characteristics of the one or more voltage signals are determined. Afterwards the characteristics of the one or more voltage signals are compared with one or more characteristics of an audio trigger command. Activation of an audio user interface is then activated on the basis of the comparison.

FIELD OF THE APPLICATION

The present application relates to a method and apparatus. In someembodiments the method and apparatus relate to an audio user interface.

BACKGROUND OF THE APPLICATION

Some known electronic devices use speech recognition. Electronic devicesutilising voice commands and speech-to-text functionality can enablehands-free use and better accessibility. For example, a mobile phonewith hands-free functionality enables a user to make a phone call ordictate a text message while driving a car.

One known way for a user to start a speech recognition function in anelectronic device is to press a button or select the feature from a menuof the electronic device's user interface. This means that a usertypically has to activate the speech recognition functionality with ahand or even both hands. However, a user may not be able to touch theelectronic device to activate a speech recognition function. Forexample, a user may be washing dishes or riding a bicycle and does notwant to touch or cannot touch the electronic device.

One proposal is to configure an electronic device so that a speechrecognition function is on all the time. However, this may not befeasible because a processor may require large amounts of processingcapacity which can consume too much power and drain a power cell of theelectronic device too quickly. For example, a processor running a speechrecognition function can draw a current in the order of a hundredmilliamps from the power cell when calculating fast Fourier transformand processing audio to determine whether the audio contains spokenwords.

In another known arrangement a signal is captured with an in-earmicrophone, which detects a specific user humming sequence or a voicecommand. The ear piece attenuates surrounding noises from entering theear canal making the user's voice to be easier to separate from othersounds. However, the detection of the voice command may similarly drainthe power cell of an electronic device as quickly as permanently onspeech recognition.

In one known arrangement a speech recognition function is activated whena user claps or whistles. Typically, the electronic device activates thespeech recognition function when the user's clapping or whistling isover a certain volume. The arrangement is problematic and can lead tounnecessary activation of the speech recognition function, especially innoisy environments.

Embodiments of the application aim to address one or several of theabove issues.

SUMMARY OF THE APPLICATION

In a first embodiment there is provided a method comprising; convertingan audio frequency domain signal into one or more voltage signals;determining the characteristics of the one or more voltage signals;comparing the characteristics of the one or more voltage signals withone or more characteristics of an audio trigger command; and initiatingactivation of an audio user interface on the basis of the comparison.

Preferably the determining the characteristics of the one of morevoltage signals comprises determining whether the one or more voltagesignals are in one of a plurality of adjacent voltage ranges.

Preferably the plurality of voltage ranges are defined by a plurality ofvoltage comparators, the voltage comparators detecting when a voltagesignal exceeds a voltage threshold.

Preferably the audio user interface is activated when voltage rangeinformation of the one or more voltage signals of the converted audiofrequency domain signal matches voltage range information of the audiotrigger command.

Preferably the method comprises determining that the audio frequencydomain signal matches the audio trigger command when the differencebetween the voltage range information of the converted audio frequencydomain signal and the voltage range information of the audio trigger isless than a threshold.

Preferably the voltage range information of the audio trigger command isdetermined before the audio frequency domain signal is captured.

Preferably the audio frequency signal is converted into one or morevoltage signals with a frequency-to-voltage converter. Preferably theaudio frequency domain signal is received from a microphone.

Preferably the determining comprises storing the one or more voltagesignals in a buffer for a time period.

Preferably the determining the characteristics of the one or morevoltage signals is carried out over a time period.

Preferably the activating comprises sending a signal configured toactivate another processor configured to perform the audio userinterface.

In another embodiment there is provided an apparatus comprising: afrequency to voltage converter configured to convert an audio frequencydomain signal into one or more voltage signals; a plurality of voltagedeterminers configured to determining the characteristics of the one ormore voltage signals; a processor configured to compare thecharacteristics of the one or more voltage signals with one or morecharacteristics of an audio trigger command and initiate activation ofan audio user interface on the basis of the comparison.

Preferably the plurality of voltage determiners are configured todetermine whether the one or more voltage signals are in one of aplurality of adjacent voltage ranges. Preferably the voltage determinersquantize one or more voltage signals. More preferably the voltagedeterminers are configured to sort one or more voltage signals into oneor more different voltage ranges. Preferably the one or more differentvoltage ranges are predetermined or dynamically determined.

Preferably the plurality of voltage determiners are a plurality ofvoltage comparators, the voltage comparators configured to detect when avoltage signal exceeds a voltage threshold.

Preferably the processor is configured to activate the audio userinterface when voltage range information of the one or more voltagesignals of the converted audio frequency domain signal matches voltagerange information of the audio trigger command.

Preferably the processor is configured to determine that the audiofrequency domain signal matches the audio trigger command when thedistance between the voltage range information of the converted audiofrequency domain signal and the voltage range information of the audiotrigger is less than a threshold.

Preferably the processor is configured to determined the voltage rangeinformation of the audio trigger command before the audio frequencydomain signal is captured. Preferably the audio frequency domain signalis received from a microphone.

Preferably the apparatus comprises a buffer configured to store the oneor more voltage signals in for a time period. Preferably the processoris configured to determine the characteristics of the one or morevoltage signals over a time period.

Preferably the processor is configured to send a signal for activatinganother processor configured to perform the audio user interface.

In another embodiment there is a computer program comprising code meansadapted to perform the steps of any of the previous methods.

In yet another embodiment there is provided an apparatus comprising;means for converting an audio frequency domain signal into one or morevoltage signals; means for determining the characteristics of the one ormore voltage signals; means for comparing the characteristics of the oneor more voltage signals with one or more characteristics of an audiotrigger command; and means for initiating activation of an audio userinterface on the basis of the comparison.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present application and as to how thesame may be carried into effect, reference will now be made by way ofexample to the accompanying drawings in which:

FIG. 1 illustrates a schematic block diagram of an apparatus accordingto some embodiments;

FIG. 2 illustrates an expanded schematic view of an apparatus accordingto some embodiments;

FIG. 3 shows an apparatus according to some other embodiments;

FIG. 4 illustrates a flow diagram of capturing a voice trigger commandaccording to some embodiments;

FIG. 5 illustrates a more detailed method for capturing a voice triggercommand according to some embodiments;

FIG. 6 illustrates a flow diagram of a method according to someembodiments;

FIG. 7 illustrates a schematic representation of an algorithm accordingto some embodiments;

FIG. 8 illustrates an output of a frequency-to-voltage converter with aspeech synthesizer saying “wake up” with different parameters;

FIG. 9 illustrates an output of a frequency-to-voltage converter withvoice samples of the same person saying “wake up”;

FIG. 10 illustrates a spectrum of the words “wake up” spoken by the samespeaker.

DETAILED DESCRIPTION

The following describes apparatus and methods for activating an audiouser interface with an audio trigger, such as a voice trigger command.

In this regard reference is made to FIG. 1 which discloses a schematicblock diagram of an example electronic device 100 or apparatus suitablefor employing embodiments of the application. The electronic device 100is configured to provide an audio user interface, such as a voiceactivated user interface according to some embodiments.

The electronic device 100 is in some embodiments a mobile terminal, amobile phone or user equipment for operation in a wireless communicationsystem. In other embodiments, the electronic device is a digital camera,a camcorder, a portable dictation device, personal digital assistant(PDA), laptop or any other electronic device suitable for capturingsound.

The electronic device 100 comprises a microphone 102 connected to anaudio module 104 which is linked to a processor 110. The processor 110is linked to a transceiver (TX/RX) 108, to a user interface (UI) 106 andto memory 112.

The processor 110 in some embodiments can be configured to executevarious program codes. For example, the implemented program code cancomprise a code for controlling the microphone 102 to capture sound. Theimplemented program codes, in some embodiments, comprise audio digitalprocessing or configuration code. The implemented program codes in someembodiments further comprise additional code for further processing ofaudio signals. The implemented program codes can in some embodiments bestored, for example, in the memory 112 and specifically in a programcode section 114 of the memory 112 for retrieval by the processor 110whenever needed. The memory 112 in some embodiments can further providea section 116 for storing data, for example, data that has beenprocessed in accordance with the application.

The electronic device 100 can comprise an audio module 104 or anysuitable means for detecting a voice trigger command. The audio module104 is connected to a microphone 102 or other suitable audio transduceror means for capturing audio in the environment of the electronic device100. The audio module 104 in some embodiments can be an applicationspecific integrated circuit. Alternatively or additionally the audiomodule 104 can be integrated with the electronic device 100. In otherembodiments the audio module 104 can be separate from the electronicdevice 100. This means the processor 110 in some embodiments can receivea modified signal from an external device comprising the audio module104.

The microphone 102 in some embodiments can be an audio sensor comprisinga dynamic or moving coil, a piece of electric transducer, anelectrostatic transducer or a transducer array comprisingmicroelectromechanical systems (MEMS) microphone, electret condensermicrophone (ECM) or any other suitable means or microphone componentsfor capturing sound. Additionally or alternatively the microphone 102comprises a multi function device (MFD). In some preferred embodimentsthe microphone 102 is an MEMS microphone comprising a microphonemembrane.

In some embodiments a MEMS microphone can be used. A MEMS microphoneoffers some advantages over an electret condenser microphone (ECM),including advantages in manufacturability, production volume scalabilityand stability in varying environments, as non-limiting examples. It canbe challenging to design an acoustically optimized MEMS microphonepackage because package design requirements are largely set by themechanical interfaces of the device in which the MEMS microphone is tobe used. For example, the design requirements may depend on how andwhere the MEMS microphone is integrated in the device.

In some embodiments, the MEMS microphone comprises two components: aMEMS chip and an application specific integrated circuit (ASIC) chip.Both the MEMS and ASIC chips are mounted on a substrate printed wiringboard (PWB) and are connected together with at least one bond wire. Themicrophone is incorporated in a casing that has one or more sound portsfor receiving acoustic pressure waves. The MEMS chip can for exampleincludes a condenser microphone element etched in silicon. The ASIC chipin some embodiments include a pre-amplifier, an analogue-to-digitalconverter and a charge pump for biasing the MEMS microphone element. Insome embodiments, the MEMS chip elements are included in the ASIC.Moreover, the ASIC can include an analogue-to-digital converter (ADC)and/or a charge pump, for example. The ASIC detects the capacitivevariations, converts them into electrical signals and passes them toappropriate processing means, such as a baseband processor or anamplifier.

The audio module 104 will now be discussed in reference to FIG. 2. FIG.2 discloses an expanded schematic view of the microphone 102, the audiomodule 104 and the processor 110.

In some embodiments the processor 110 is linked by the audio module 104to the microphone 102 and the microphone 102 can detect sound from theenvironment of the electronic device 100 and generate a signal. Themicrophone 102 sends the signal to the frequency-to-voltage converter202. The frequency-to-voltage converter 202 converts the frequency ofthe pulse received from the microphone 102 to a voltage. Thefrequency-to-voltage converter 202 outputs a voltage which isproportional to sound frequency. The output signal of thefrequency-to-voltage converter 202 is sent to an optional low passfilter 204 for removing noise from the signal. The low pass filter 204then sends the filtered signal to an analogue-to-digital converter 206.The analogue-to-digital converter digitises the analogue signal and thedigital output from the analogue-to-digital converter 206 is sent to alow power controller 208. The low power controller 208 can analyse thedigital output of the analogue-to-digital converter 206 and can send asignal to the processor 110.

FIG. 3 illustrates a circuit diagram of an apparatus according to someembodiments. In some embodiments the output from the microphone 102 issent to an amplifier 302. The output from the microphone 102 can beamplified depending on the signal. In some embodiments no amplificationmay be needed if the output from the microphone 102 is above a certainthreshold.

The output from the amplifier 302 is sent to the frequency-to-voltageconverter 202, the low pass filter 204, the analogue-to-digitalconverter 206 and the low power controller 208 as discussed with theembodiments as illustrated in FIG. 2.

In some embodiments the analogue-to-digital converter 206 comprises aplurality of comparators 304 a, 304 b, 304 c, 304 d, 304 e, 304 n. Theoutputs of each comparator are connected to the low power controller 208or suitable means for controlling. In some embodiments the low powercontroller 208 is a microcontroller.

In some embodiments the analogue-to-digital converter does not encode ananalogue signal to a digital signal. The analogue-to-digital convertercomprises comparators 304 a, 304 b, 304 c, 304 d, 304 e, 304 n which areconfigured to quantized the analogue signal. In this way, theanalogue-to-digital converter can comprise any suitable means forquantizing the analogue signal.

The implementation of activating an audio user interface with theelectronic device 100 as shown in FIG. 1 will now be described withreference to FIGS. 4 and 5. FIGS. 4 and 5 illustrate flow diagrams of amethod for capturing a voice trigger command for configuring theelectronic device 100 according to some embodiments.

In some embodiments a user may wish to activate a speech recognitionfunctionality of an electronic device 100 without handling theelectronic device 100. In order for the electronic device to efficientlyprovide a complete hands-free audio user interface, a voice triggercommand is captured during a configuration procedure. The captured voicetrigger command is then subsequently used to compare other voicecommands captured by the electronic device 100.

A user activates the configuration of a voice trigger application asshown in step 402. A user can configure the voice trigger application byselecting an appropriate setting of the electronic device 100. The voicetrigger application can be stored in some embodiments in the memory 112of the electronic device 100. The processor 110 then executes the voicetrigger application. After the voice trigger application has beenactivated, the processor 110 captures the voice trigger commandinitiated as shown in step 404. The user then provides a voice triggercommand to the electronic device 100 which can subsequently trigger theaudio user interface for the user as shown in step 406. The processor110 can store the captured voice trigger command in memory 112.

The same voice trigger command provided by the user at a later time canthen be spoken aloud by the user and used to activate the audio userinterface.

Once the processor 110 has captured the voice trigger command and storedthe voice trigger command in memory 112, the processor 110 determines ifthe voice trigger command has been successfully captured. If the userneeds to repeat the voice trigger command again, the processor 110repeats the step of 406.

Some embodiments will now be described with reference to FIG. 5. FIG. 5discloses a more detailed flow diagram for capturing the voice triggercommand. The user initiates the configuration of the voice triggerapplication as shown in step 502, which is similar to the step of 402.In some embodiments a user selects the voice user interface settings ina menu in the electronic device 100 in order to activate the voicerecognition. The user then indicates to the electronic device 100 thatcapturing the voice trigger command is to be initiated as shown in step504. Step 504 is represented in FIG. 5 as several discrete sub steps 504a, 504 b, 504 c. In some embodiments the user can indicate to theelectronic device that the voice trigger command is to be captured bymanually inputting an instruction as shown in step 504 a. In someembodiments the user can select “OK” manually from the user interface ofthe electronic device 100 to start the voice trigger command capture. Insome other embodiments the processor 110 can start recording to capturethe voice trigger command after a period of time.

The electronic device 100 instructs the user that a voice triggercommand is required for activating the audio user interface. For examplein some embodiments the electronic device 100 can prompt the user toprovide a voice trigger command as shown in step 504 b. The user maythen provide a name or a “magic word” for the voice trigger command,which the user wants to use as a trigger for activating the audio userinterface of the electronic device 100.

In some embodiments the user repeats the voice trigger command a numberof times as shown in step 504 c. In some embodiments, the processor 110detects the start and the end of the voice trigger command by detectingsilence between repetitions of the voice trigger command spoken by theuser. In the example shown in FIG. 5 the trigger command word is enteredthree times, however trigger command word entry can be more or less than3 times.

The user provides a voice trigger command aloud and the microphone 102detects the voice trigger command. The microphone 102 can then send theanalogue signal to audio module 104 for capturing the voice triggercommand and configuring the low power controller 208. The signals fromthe microphone 102 are send to the analogue-to-digital converter via thefrequency-to-voltage converter 202 and the low pass filter 204 asdiscussed with reference to FIGS. 2 and 3.

In some embodiments the analogue-to-digital converter 206 comprises aset of comparators 304 a-304 n which are used to cover a frequencyrange. In some embodiments a plurality of comparators can be used tocover a range from 0 Hz to 5 kHz or any suitable frequency range fordetecting voice sounds. The comparators can be configured to detectfrequencies separated by steps of 1000 Hz.

For example the voice trigger command could be “activate”. A user maypronounce the voice trigger command “activate” as three separatesyllables or sounds.

The voice trigger commands can have syllables which have differentfrequency spectrums and therefore detection of difference syllables canbe made with a relatively coarse analogue-to-digital converter.

In this way, if the voice trigger command is the word “activate”, thevoice trigger command comprises three syllables of “ak”, “thi” and“veit”. Each syllable has different frequency components and thecomparator 304 a-304 n outputs can be different for each syllable. Forexample the comparator 304 a-304 n outputs might be 000011, 011111 and000111 for the syllables “ak”, “thi” and “veit” respectively. FIG. 8shows the output of the frequency-to-voltage converter of a speechsynthesiser saying the phrase “wake up” using different parameters. FIG.8 illustrates that different parameters such as cadence, pitch,intonation can affect the output. FIG. 9 shows the output of thefrequency-to-voltage converter showing of the same person saying thephrase “wake up” a number of times. FIG. 9 illustrates that variationsin speech can occur even when the same person says the same phrasedifferent times.

The processor 110 determines when the low power controller 208 hasdetected the same voice trigger command if the low power controller 208indicates to the processor 110 that the outputs of the comparators 304a-304 n for the voice trigger command are the same over a plurality ofrepetitions. If the processor 110 determines that the capture of thevoice trigger command was successful, as shown in step 506, theprocessor 110 indicates to the user that the voice activated audio userinterface is active as shown in step 508.

If the processor 110 determines that the voice trigger command has notbeen repeated a plurality of times the processor is configured toinitiate display an error message to the user. In some embodiments theelectronic device 100 can display a prompt to ask if the user would liketo try recording again as shown in step 510.

When the processor 110 determines that the voice trigger command hasbeen successfully captured, the microcontroller stores the voice triggercommand in a lookup table in a memory 210 of the low power controller208.

The implementation of activating an audio user interface havingsuccessfully detected a voice trigger command will now be described withreference to FIG. 6. FIG. 6 discloses a flow diagram illustrating someembodiments for activating an audio user interface.

The microphone 102 can be configured to, in some embodiments, “listen”for audio, and in particular voice sounds, as shown in step 602. In someembodiments the microphone 102 is constantly detecting audio in theenvironment of the electronic device 100. Alternatively, in someembodiments the microphone periodically “listens” or detects for audioin the environment of the electronic device 100.

When a user gives the voice trigger command, for example “activate”, themicrophone 102 sends the analogue signals to the frequency-to-voltageconverter 202. The frequency-to-voltage converter will output a voltagedepending on a dominant frequency component at its input. The output ofthe frequency-to-voltage converter 202 is sent to a low pass filter 204.The low pass filter suppresses any frequency changes which are fasterthan frequency changes of an average word. In this way, the output ofthe low pass filter 204 comprises predominately of voice frequencies.The low pass filter 204 can in some embodiments output the signal to thecomparators 304 a-304 n of the analogue-to-digital converter. Eachcomparator 304 a-304 n is configured to detect a particular voltagelevel which corresponds to a range of frequencies because thefrequency-to-voltage converter provides a linear conversion of frequencyto voltage. This means that since the outputs of the comparators 304a-304 n are connected to the low power controller 208, the lower powercontroller 208 can make an approximate determination of the frequenciescaptured by the microphone 102.

The comparators 304 a-304 n are components configured to determine whenan input voltage is lower or higher than a given reference voltage. Thecomparators 304 a-304 n are configured to output a signal of “1” or “0”depending on the determination of whether the input voltage is lower orhigher than the reference voltage. The voice trigger command comprises afrequency range which when the voice trigger command is input into thefrequency to voltage converter 202 has an associated voltage range. Insome embodiments the threshold voltages of the comparators are selectedto divide the voltage range of a voice trigger command output from thefrequency to voltage converter 202 into equal amounts. In somealternative embodiments other methods of dividing up the voltage rangecan be used including one or more of pseudo-acoustic divisions, logdivisions or overlapping divisions. In some embodiments the voltagerange is divided into exponential threshold, such that the thresholds ofthe comparators 304 a-304 n satisfy the following (1):

Threshold voltage=k*2^(n)  (1)

where k is a constant and n is the number of the comparator.

In some embodiments, the plurality of comparators are configured todetect a plurality of voltage levels V1, V2, . . . , Vn. In someembodiments the comparators have threshold voltages of 0.1V, 0.2V, 0.4V,0.8V within a 0-1.6 output voltage swing or peak to trough amplitude ofthe voltage signal. In some other embodiments the thresholds of thecomparators 304 a-304 n are configured to generate an equal number oftransitions for the voice trigger command. In some embodiments thethresholds of the comparators 304 a-304 n are set during theconfiguration of the user interface as described in reference to FIG. 4.For example, the thresholds are set with respect to the captured voicetrigger command during step 408.

Once the microphone 102 has captured the audio as shown in step 604, thelow power controller 208 determines whether the captured audio matchesthe voice trigger command as shown in step 606.

The determination whether the captured audio matches the voice triggercommand stored in the low power controller 208 lookup table will now bediscussed with reference to FIG. 7. FIG. 7 discloses an algorithm fordetermining the state of the comparators 304 a-304 n and activating thelow power controller 208 on the basis thereof.

Each comparator 304 a-304 n can in some embodiments be described ashaving a state of “0” or “1”. A state of 0 reflects a negative statethat no voltage equal to or higher than the predetermined voltage levelis present and a second state 1 which reflects a positive state that avoltage equal to or higher than a predetermined level is detected. Forexample, a comparator when no audio is detected in a frequency rangeassociated with the comparator, the comparator is in a negative state(e.g. 0). FIG. 10 illustrates frequency to digital conversion comparedagainst selected reference voltages of the comparators in someembodiments.

Each comparator state can be measured using an internal timer and thevalue of each comparator can be stored in an input buffer included ineach comparator 304 a-304 n. From each comparator 304 a-304 n atransition time is associated with each value. Values are ordered bytheir transition times wherein the most recent transition time is putfirst and the oldest value is discarded. This means when a new value isdetermined, the oldest value is discarded. When the microphone 102detects audio which is a voice trigger command one or more of thecomparators may change state as shown in step 802. The microcontroller208 then determines the state duration as shown in step 804. The stateduration can be put into the buffer and the oldest value in the bufferis removed as shown in step 806. The low power controller 208 thendetermines the Euclidian distance of the values signals received at oneor more comparators 304 a-304 n to the values of the pre-recorded voicetrigger command stored in the memory 210 of the low power controller 208as shown in step 808. The low power controller 208 can then calculatethe total Euclidian distance for all other comparators using theequation [1].

sqrt(sum_i(pow(buffer[i]−model[i],2)))  [1]

If the result of the Euclidian distance is lower than a threshold thenthe low power controller 208, in some embodiments, can wake theprocessor 110 from a sleep mode, in which the processor 110 uses a smallamount of power.

This means that the “signature” of the captured audio is compared to the“signature” of the trigger word. When the error variation of thecaptured audio is small compared to the recorded trigger word, thecaptured audio is accepted and the low power controller 208 initiatesactivating the processor 110. Once the low power controller 208determines that the captured audio matches the voice trigger commandthen the microcontroller initiates activating the processor 110 toactivate the audio used interface as shown in steps 608 and 812. The lowpower controller 208 can then send an interrupt to the processor 110.The processor 110 can activate on receiving the interrupt from the lowpower controller 208 and the processor can be configured to performspeech recognition tasks. Alternatively, when the result is higher thana predetermined threshold then the low power controller 208 does notwake the processor 110 from sleep.

In some embodiments, the processor 110 then waits for the microphone 102to capture further audio from the environment of the electronic device100. In some embodiments the microphone can send signals to theprocessor 110 without sending them to the audio module. In some otherembodiments when the processor 110 is active, the signals from themicrophone 102 are sent to another analogue-to-digital converter (notshown). The other analogue-to-digital converter can comprise morecomparators and provide a greater frequency resolution than with respectto the analogue-to-digital converter comprised in the audio module 204.

The processor can determine whether the audio user interface has timedout as shown in step 610. This means that the processor 110 in someembodiments can only perform the user interface action when theprocessor 110 determines that an audio instruction has been providedwithin a predetermined time limit. In some embodiments, thepredetermined time limit can be 1 minute or any other suitable timelimit for received audio instructions. This means that even when thevoice trigger command is recognised in normal speech the processor 110can time out and return to a sleep mode before a valid instruction ofthe audio user interface is captured. It should be unlikely that thevoice trigger command will be unintentionally followed with a validaudio user interface command, especially when the user selects adistinctive word as the voice trigger command.

When the processor 110 determines that the audio user interface has nottimed out the processor 110 can capture audio in the environment of theelectronic device 100 as shown in step 612. The processor 110 determineswhether the audio instruction captured in step 612 matches audio userinterface actions as shown in step 614. The audio user interface asshown in step 614 can use speech recognition techniques such as fastFourier transforms. In some embodiments the processor uses other speechrecognition algorithms. When the processor 110 determines that an audioinstruction has been issued, the processor 110 can initiate performingthe action associated with the audio instruction as shown in step 616.Alternatively, when the processor 110 determines that there is an audioinstruction recognition error, for example when the captured voice isnot a valid audio instruction, as shown in step 616, the processor 110can repeat the capture of audio instruction 612 until the processor 110has determined whether the audio user interface has timed out.

When the audio user interface has timed out, then the processor 110 canreturn to a sleep mode and the low power controller 208 can again listenfor the voice trigger command. Advantageously an electronic device suchas a mobile phone can be woken up from sleep without a user touching thedevice. Some embodiments prove an arrangement whereby a low powermicrocontroller is always on and determines whether the voice triggercommand has been issued and if so the processor which executes the fullspeech recognition is activated. This means that battery life can beextended and the electronic device can provide a fully hands freeexperience for a user.

It shall be appreciated that the term electronic device and userequipment is intended to cover any suitable type of wireless userequipment, such as mobile telephones, portable data processing devicesor portable web browsers.

In general, the various embodiments of the invention may be implementedin hardware or special purpose circuits, software, logic or anycombination thereof. For example, some aspects may be implemented inhardware, while other aspects may be implemented in firmware or softwarewhich may be executed by a controller, microprocessor or other computingdevice, although the invention is not limited thereto. While variousaspects of the invention may be illustrated and described as blockdiagrams, flow charts, or using some other pictorial representation, itis well understood that these blocks, apparatus, systems, techniques ormethods described herein may be implemented in, as non-limitingexamples, hardware, software, firmware, special purpose circuits orlogic, general purpose hardware or controller or other computingdevices, or some combination thereof.

The embodiments of this invention may be implemented by computersoftware executable by a data processor of the mobile device, such as inthe processor entity, or by hardware, or by a combination of softwareand hardware. Further in this regard it should be noted that any blocksof the logic flow as in the Figures may represent program steps, orinterconnected logic circuits, blocks and functions, or a combination ofprogram steps and logic circuits, blocks and functions. The software maybe stored on such physical media as memory chips, or memory blocksimplemented within the processor, magnetic media such as hard disk orfloppy disks, and optical media such as for example DVD and the datavariants thereof, CD.

The memory may be of any type suitable to the local technicalenvironment and may be implemented using any suitable data storagetechnology, such as semiconductor-based memory devices, magnetic memorydevices and systems, optical memory devices and systems, fixed memoryand removable memory. The data processors may be of any type suitable tothe local technical environment, and may include one or more of generalpurpose computers, special purpose computers, microprocessors, digitalsignal processors (DSPs), application specific integrated circuits(ASIC), gate level circuits (such as field programmable gate array—FPGAcircuits) and processors based on multi-core processor architecture, asnon-limiting examples.

Embodiments of the inventions may be practiced in various componentssuch as integrated circuit modules. The design of PWB and RF designs areby and large a highly automated process. Complex and powerful softwaretools are available for converting a design into a Printed Wired Boarddesign ready to be etched and formed on a substrate.

Programs automatically route conductors and locate components on asubstrate using well established rules of design as well as libraries ofpre-stored design modules. Once the design for a substrate or circuithas been completed, the resultant design, in a standardized electronicformat may be transmitted to a fabrication facility or for fabrication.

As used in this application, the term ‘circuitry’ refers to all of thefollowing:

-   -   (a) hardware-only circuit implementations (such as        implementations in only analogue and/or digital circuitry) and    -   (b) to combinations of circuits and software (and/or firmware),        such as: (i) to a combination of processor(s) or (ii) to        portions of processor(s)/software (including digital signal        processor(s)), software, and memory(ies) that work together to        cause an apparatus, such as a mobile phone or server, to perform        various functions and    -   (c) to circuits, such as a microprocessor(s) or a portion of a        microprocessor(s), that require software or firmware for        operation, even if the software or firmware is not physically        present.

This definition of ‘circuitry’ applies to all uses of this term in thisapplication, including any claims. As a further example, as used in thisapplication, the term ‘circuitry’ would also cover an implementation ofmerely a processor (or multiple processors) or portion of a processorand its (or their) accompanying software and/or firmware. The term‘circuitry’ would also cover, for example and if applicable to theparticular claim element, a baseband integrated circuit or applicationsprocessor integrated circuit for a mobile phone or similar integratedcircuit in server, a cellular network device, or other network device.

The foregoing description has provided by way of exemplary andnon-limiting examples a full and informative description of theexemplary embodiment of this invention. However, various modificationsand adaptations may become apparent to those skilled in the relevantarts in view of the foregoing description, when read in conjunction withthe accompanying drawings and the appended claims. However, all such andsimilar modifications of the teachings of this invention will still fallwithin the scope of this invention as defined in the appended claims.

Indeed in there is a further embodiment comprising a combination of oneor more of any of the other embodiments previously discussed.

1. A method comprising; converting an audio signal into one or morevoltage signals; determining the characteristics of the one or morevoltage signals; comparing the characteristics of the one or morevoltage signals with one or more characteristics of an audio triggercommand; and initiating activation of user interface on the basis of thecomparison.
 2. A method according to claim 1 wherein the determining thecharacteristics of the one of more voltage signals comprises determiningwhether the one or more voltage signals are in one of a plurality ofadjacent voltage ranges.
 3. A method according to claim 1 wherein theplurality of voltage ranges are defined by a plurality of voltagecomparators, the voltage comparators detecting when a voltage signalexceeds a voltage threshold.
 4. A method according to claim 2 whereinthe user interface is activated when voltage range information of theone or more voltage signals of the converted audio signal matchesvoltage range information of the audio trigger command.
 5. A methodaccording to claim 4 wherein the method comprises determining that theaudio signal matches the audio trigger command when the differencebetween the voltage range information of the converted audio signal andthe voltage range information of the audio trigger is less than athreshold.
 6. A method according to claim 4 wherein the voltage rangeinformation of the audio trigger command is determined before the audiosignal is captured wherein the captured audio signal is received from amicrophone.
 7. A method according to claim 1 wherein the audio signal isconverted into one or more voltage signals with a frequency-to-voltageconverter.
 8. (canceled)
 9. A method according to claim 1 wherein thedetermining comprises storing the one or more voltage signals in abuffer for a time period.
 10. A method according to claim 1 wherein thedetermining the characteristics of the one or more voltage signals iscarried out over a time period.
 11. A method according to claim 1wherein the activating comprises sending a signal configured to activateanother processor configured to perform the user interface.
 12. Anapparatus comprising: a frequency to voltage converter configured toconvert an audio signal into one or more voltage signals; a plurality ofvoltage determiners configured to determine the characteristics of theone or more voltage signals; a processor configured to compare thecharacteristics of the one or more voltage signals with one or morecharacteristics of an audio trigger command and initiate activation of auser interface on the basis of the comparison.
 13. An apparatusaccording to claim 12 wherein the plurality of voltage determiners areconfigured to determine whether the one or more voltage signals are inone of a plurality of adjacent voltage ranges.
 14. An apparatusaccording to claim 12 wherein the plurality of voltage determiners are aplurality of voltage comparators, the voltage comparators configured todetect when a voltage signal exceeds a voltage threshold.
 15. Anapparatus according to claim 12 wherein the processor is configured toactivate the user interface when voltage range information of the one ormore voltage signals of the converted audio signal matches voltage rangeinformation of the audio trigger command.
 16. An apparatus according toclaim 15 wherein the processor is configured to determine that the audiosignal matches the audio trigger command when the distance between thevoltage range information of the converted audio signal and the voltagerange information of the audio trigger is less than a threshold.
 17. Anapparatus according to claim 15 wherein the processor is configured todetermined the voltage range information of the audio trigger commandbefore the audio signal is captured.
 18. An apparatus according to claim12 wherein the audio signal is received from a microphone.
 19. Anapparatus according to claim 12 wherein the apparatus comprises a bufferconfigured to store the one or more voltage signals in for a timeperiod.
 20. An apparatus according to claim 12 wherein the processor isconfigured to determine the characteristics of the one or more voltagesignals over a time period.
 21. An apparatus according to claim 12wherein the processor is configured to send a signal for activatinganother processor configured to perform the user interface. 22.(canceled)